ADOT putting the 'smooth' back into stretch of I-17 in Phoenix

ADOT putting the 'smooth' back into stretch of I-17 in Phoenix

ADOT putting the 'smooth' back into stretch of I-17 in Phoenix

April 27, 2017

PHOENIX – Drivers are already noticing a smoother ride on Interstate 17, and there’s more on the way as crews work to resurface more than 10 miles of the freeway between the downtown area and north Phoenix with a fresh layer of rubberized asphalt.

As the Arizona Department of Transportation’s $9.8 million I-17 Improvement Project between Dunlap and 19th avenues approaches the halfway mark, crews have already paved six miles southbound and five miles northbound.

The paving, which started in March, requires sections of the freeway in one direction to be closed on most weekends until mid-June, including northbound I-17 between McDowell and Camelback roads from 10 p.m. Friday to 5 a.m. Monday (May 1). The Interstate 10 ramps connecting to northbound I-17 at the “Stack” interchange also will be closed.

The entire I-17 project, including final lane striping, will be completed this summer.

ADOT’s project team is working to limit the traffic impacts, including scheduling paving northbound this weekend with fans heading to Arizona Diamondbacks games and other events in and around downtown. In addition, there will no closure over Memorial Day weekend in late May.

ADOT’s overhead message boards will alert drivers to the closures and available alternate routes, including State Route 51.

Rubberized asphalt, which includes melted rubber from recycled tires blended into its mixture, is best applied to the freeway within a pavement temperature range that’s higher than 75 degrees. Such temperatures generally occur during spring and fall, when most rubberized asphalt resurfacing is done.

ADOT uses rubberized asphalt on many freeways and highways because it has proven to be a durable pavement that provides a smooth ride. It has also gained favor over time for reducing traffic noise in neighborhoods adjacent to freeways.

The I-17 Improvement Project actually started last fall with sidewalk and wheelchair ramp improvements at a number of cross street interchanges. Crews also are upgrading safety fences on overpasses above I-17.

Other work has included I-17 drainage improvements near Durango Street, new signs and concrete-barrier upgrades.

ADOT will provide updates on the I-17 resurfacing and scheduled closures on the agency’s website, azdot.gov, and Twitter feed (@ArizonaDOT).

Quiet Pavement Pilot Program

Quiet Pavement Pilot Program

Quiet Pavement Pilot Program

December 15, 2011

Back in the early 2000s ADOT started to hear from drivers who said certain stretches of Valley freeways seemed quieter than others.

ADOT and the Maricopa Association of Governments (MAG) noticed a difference, too.

It seemed that areas paved with an asphalt rubber friction course (rubberized asphalt), which MAG funded through the Regional Transportation Plan, were less noisy than freeway surfaces with cement concrete pavement.

ADOT set out to determine whether the rubberized asphalt really did make any difference when it comes to noise abatement. ADOT officials also wanted to know whether the perceived noise-reducing properties of the rubberized asphalt would last as the pavement aged.

Quiet Pavement Pilot Program

After some initial studies showed promise, ADOT, in connection with the Federal Highway Administration, developed the Quiet Pavement Pilot Program in 2003.

The program allows ADOT to use rubberized asphalt on selected freeway sections in the Valley in order to test out and study its noise mitigation properties.

According to the FHWA description, the program is intended to “demonstrate the effectiveness of quiet pavement strategies and to evaluate any changes in their noise mitigation properties over time. Current knowledge on changes over time is extremely limited. Thus, the programs will collect data and information for at least a 5-10 year period, after which the FHWA will determine if policy changes to a state DOT’s noise program are warranted.”

In other words, this study is going to show whether or not the noise mitigating effects of rubberized asphalt last the test of time.

That’s important to know because right now state DOTs cannot consider rubberized asphalt as a method to lessen highway noise. Noise walls and other tools are used primarily to meet noise abatement requirements.

If this study proves rubberized asphalt helps alleviate some road noise over years of use, states could potentially start using rubberized asphalt as an additional tool to help build quieter roads.

Findings to date

The study has shown so far …

Rubberized asphalt works best at high speeds and for average-sized passenger vehicles. It doesn’t have as much of a quieting impact at slow speeds or for larger trucks or motorcycles It’s not a solution for all climates Rubberized asphalt produces an average noise reduction of about 4 to 5 decibels over time.

Where we are today …

We have about three years remaining in the pilot study and we want to hear from you … the people who drive on Maricopa County freeways.

Public comment is an important part of the pilot program. ADOT has committed to collect and document public reactions on the rubberized asphalt for the study.

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